From 858d52f66e7c87be08ff3b90a4dd17f06684b445 Mon Sep 17 00:00:00 2001
From: David Ra <davidradeveloper@gmail.com>
Date: Mon, 29 Feb 2016 07:47:20 -0500
Subject: [PATCH] feat(flatten): add variable-arity, add test

Closes #17
---
 src/flatten.js       | 11 +++++------
 test/flatten.test.js |  9 +++++++++
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/flatten.js b/src/flatten.js
index 25ed789d..de052030 100644
--- a/src/flatten.js
+++ b/src/flatten.js
@@ -3,14 +3,13 @@ export default flatten
 /**
  * Original Source: http://stackoverflow.com/a/15030117/971592
  *
- * This method will flatten an array given to it.
+ * This method will flatten arrays given to it.
  *
- * @param {Array} arr - The array to flatten
+ * @param {...Array} arrays - The array(s) to flatten
  * @return {Array} - The flattened array
  */
-function flatten(arr) {
-  return arr.reduce(function flattenReducer(flat, toFlatten) {
-    return flat.concat(Array.isArray(toFlatten) ? flatten(toFlatten) : toFlatten)
+function flatten() {
+  return [].slice.call(arguments).reduce(function flattenReducer(flat, toFlatten) {
+    return flat.concat(Array.isArray(toFlatten) ? flatten.apply(null, toFlatten) : toFlatten)
   }, [])
 }
-
diff --git a/test/flatten.test.js b/test/flatten.test.js
index 6376d96f..c9a04840 100644
--- a/test/flatten.test.js
+++ b/test/flatten.test.js
@@ -7,3 +7,12 @@ test('flattens an array of arrays', t => {
   const actual = flatten(original)
   t.same(actual, expected)
 })
+
+test('flattens multiple arrays', t => {
+  const original1 = [[1, 2], 3, [4, 5]]
+  const original2 = ['A', 'b', ['C', ['d', 'E']]]
+  const original3 = [true, false, true, false]
+  const expected = [1, 2, 3, 4, 5, 'A', 'b', 'C', 'd', 'E', true, false, true, false]
+  const actual = flatten(original1, original2, original3)
+  t.same(actual, expected)
+})